Abstract:
A method of damping resonances in a rotating system is disclosed, which includes developing a representation of vibrating movement in the rotating system, taking the derivative of that representation and applying an out-of-phase active damping force based on the derivative to the rotating system to damp out the movement.
Abstract:
A disc drive (10) includes a housing (12), a central axis (80), a stationary member (34) which is fixed with respect to the housing and coaxial with the central axis, and a rotatable member (36) rotatable about the central axis with respect to the stationary member. A stator (38) is fixed with respect to the housing. A rotor (70) is supported by the rotatable member and is magnetically coupled to the stator. At least one data storage disc (16) is attached to and is coaxial with the rotatable member. A hydro bearing (37) interconnects the stationary member and the rotatable member and includes a blend of a base fluid (84) having a viscosity index of at least (110), an anti-oxidant additive, an anti-corrosive additive and an anti-wear additive, which are effective for resisting catalytic degradation in the hydro bearing.
Abstract:
A polyphase spindle DC motor (figure 1A, 1B) providing a torque (figure 1A) and an additional radial force (F, figure 1B) within the spindle motor utilizing the spindle components (magnets and stator laminations). Interaction between the magnets and currents flowing through conductors create the torque and radial force (F) required for overall stability and efficient operation of the system.
Abstract:
A hydrodynamic bearing which includes both a shaft (50) and a rotor rotating relative to one another and defining a hydrodynamic bearing in the gap (58) between the relatively rotating surfaces (60, 72).
Abstract:
A disc drive (10) includes a housing (12), a central axis (80), a stationary member (34) fixed to the housing and coaxial with the central axis, and a rotatable member (36) rotatable about the central axis with respect to the stationary member. A stator (38) is fixed to the housing. A rotor (70) is supported by the rotatable member and is magnetically coupled to the stator. A data storage disc (16) is attached to and is coaxial with the rotatable member. A hydro bearing (37) interconnects the stationary member and the rotatable member and includes a blend of base fluids (84). The base fluids are selected such that one has a viscosity that is greater than a desired viscosity for the drive, another has a viscosity that is less than the desired viscosity and the blend has a viscosity that is within a selected range of the desired viscosity.